Some areas of the Midwest were expected to warm up dramatically by the weekend.
But some still braved the freezing conditions and one woman, aged 60, was found dead in an abandoned house in Lorain, Ohio.
Detroit, which clocked in at -14 on Thursday, a 99-year record low, could hit 45 degrees on Sunday and 50 degrees Monday.
Similar problems are expected amid a rapid thaw.
America's third largest city, where about 3.8cm (1.5in) of snow fell overnight into Friday, endured its second coldest day ever recorded on Thursday, but it has been even colder in parts of the upper Midwest.
"Keeping Michiganders safe during this stretch of dangerously cold temperatures is our priority", Whitmer said.
Authorities in NY say the death of a homeless man whose frozen body was found in a suburban Buffalo bus shelter might be related to the arctic cold that has blanketed much of the northern US this week.
Governors in Illinois, Wisconsin and MI declared emergencies as the worst of the cold threatened on Wednesday.
Officials also are warning of terrible travel and road conditions, high temperatures that stay in the single digits, and wind chills that dip far below zero. The whirlwind of icy polar air forms every winter and depending on the vortex's strength it may shift or even split into pieces. In Detroit, more than two dozen water mains froze.
Environment Canada reported record-breaking snowfall at the Ottawa airport, where some 50 flights were cancelled, with an accumulation of almost a metre (more than three feet). Milwaukee's low was minus-25 degrees.
The lowest temperature recorded early morning yesterday was -34°F (-37°C) in Stonington, Michigan, according to the NWS. It said it typically operates 55 trains daily to and from the Chicago hub.
In a rare move, the U.S. Postal Service suspended mail delivery on January 30 in parts or all of several Midwest states including Michigan, North and South Dakota, Nebraska, Kansas, Minnesota, Wisconsin, Iowa, and IL.
The bitter cold has been caused by the mass of air known as the polar vortex drifting south from its usual position over the North Pole.
The Midwest's worst cold snap in two decades was created by the polar vortex, a reservoir of icy air that usually swirls over the North Pole. Local media reported that the 18-year-old was found unconscious outside a university building when temperatures were in the negative double digits in Iowa City.
Supplies were strained due to high demand from home heaters and from a fire at a natural gas compressor station in MI, officials said. By Thursday, Consumers Energy said it was "cautiously optimistic" that its requests to curb natural gas use were "having a positive effect". Most long-distance services to and from Chicago will resume on Thursday. "Motorists are encouraged to wear seat belts, reduce speeds and drive according to the conditions", it said.
"You could see the look on their faces".
Mark Zandi, chief economist at Moody's Analytics, said one reason the severe cold weather will have less impact is that, unlike a hurricane, people did not lose electric power.
A fire at the Vermont Farm Show in Essex, Vermont, led authorities to evacuate vendors and livestock to get them out of the cold.